I just installed my Reverant MS3 basic for my 05 Miata, and Tunerstudio isn't reading the AFR. I have an Innovate MTX-L, with the yellow wire connected to the factory o2 sensor location on the harness. The wideband is grounded with the engine ground. The Megasquirt is directly plugged in to the factory harness, vacuum line ran to the intake manifold, etc. I setup a new project in Tunerstudio with the instructions provided, and it seemed to work fine. I started the car and noticed that the AFR gauge in Tunerstudio was stuck on 7.90 with the needle twitching, while the car was idling at around 17, to which promptly shut the engine off. I know the Innovate MTX-L works because I previously had it wired to the factory harness/ECU with the brown narrowband and the gauge showed the wideband reading. Also, I checked the yellow wire with a multimeter with the car of, and it read 5v, which is correct because the AFR was 22.4. I've searched several forums and posts and I can't seem to find anyone who has experienced this. I've already tried calibrating the AFR (setting up a custom linear wideband with 0v 7.35 and 5v 22.39. In reality, I'm probably missing something really simple.... Any help would be greatly appreciated. Thanks in advance!

 

The instructions included with the unit specify that you need to connect the wideband's output to the yellow wire on the DB37, not to the factory O2 wire.

 

Yea, I figured it out about 5 minutes after I posted this thread. I should've posted saying so haha... I guess I was under the impression that the pigtail was completely optional due to the factory harness plug. Anyways, thank you very much Reverant! My car's been running perfectly, I drove around a few hours last night with VEAL, and have a pretty spot on tune already.

 

My miata is doing the same thing. MS3 pnp pro with mtx-L. I have my wideband output plugged into options pin "C". Is this not correct?